# Copyright (C) 2014-2021 Greenbone Networks GmbH
#
# SPDX-License-Identifier: AGPL-3.0-or-later
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

""" OSP XML utils class.
"""

import re

from typing import List, Dict, Any, Union

from xml.sax.saxutils import escape, quoteattr
from xml.etree.ElementTree import tostring, Element

from ospd.misc import ResultType


r = re.compile(  # pylint: disable=invalid-name
    r'(.*?)(?:([^\x09\x0A\x0D\x20-\x7E\x85\xA0-\xFF'
    + r'\u0100-\uD7FF\uE000-\uFDCF\uFDE0-\uFFFD])|([\n])|$)'
)


def split_invalid_xml(result_text: str) -> Union[List[Union[str, int]], str]:
    """Search for occurrence of non printable chars and replace them
    with the integer representation the Unicode code. The original string
    is splitted where a non printable char is found.
    """
    splitted_string = []

    def replacer(match):
        regex_g1 = match.group(1)
        if len(regex_g1) > 0:
            splitted_string.append(regex_g1)
        regex_g2 = match.group(2)
        if regex_g2 is not None:
            splitted_string.append(ord(regex_g2))
        regex_g3 = match.group(3)
        if regex_g3 is not None:
            splitted_string.append(regex_g3)
        return ""

    re.sub(r, replacer, result_text)
    return splitted_string


def escape_ctrl_chars(result_text):
    """Replace non printable chars in result_text with an hexa code
    in string format.
    """
    escaped_str = ''
    for fragment in split_invalid_xml(result_text):
        if isinstance(fragment, int):
            escaped_str += f'\\x{fragment:00004X}'
        else:
            escaped_str += fragment

    return escaped_str


def get_result_xml(result):
    """Formats a scan result to XML format.

    Arguments:
        result (dict): Dictionary with a scan result.

    Return:
        Result as xml element object.
    """

    result_xml = Element('result')
    for name, value in [
        ('name', result['name']),
        ('type', ResultType.get_str(result['type'])),
        ('severity', result['severity']),
        ('host', result['host']),
        ('hostname', result['hostname']),
        ('test_id', result['test_id']),
        ('port', result['port']),
        ('qod', result['qod']),
        ('uri', result['uri']),
    ]:
        result_xml.set(name, escape(str(value)))
    if result['value'] is not None:
        result_xml.text = escape_ctrl_chars(result['value'])

    return result_xml


def get_progress_xml(progress: Dict[str, int]):
    """Formats a scan progress to XML format.

    Arguments:
        progress (dict): Dictionary with a scan progress.

    Return:
        Progress as xml element object.
    """

    progress_xml = Element('progress')
    for progress_item, value in progress.items():
        elem = None
        if progress_item == 'current_hosts':
            for host, h_progress in value.items():
                elem = Element('host')
                elem.set('name', host)
                elem.text = str(h_progress)
                progress_xml.append(elem)
        else:
            elem = Element(progress_item)
            elem.text = str(value)
            progress_xml.append(elem)
    return progress_xml


def simple_response_str(
    command: str,
    status: int,
    status_text: str,
    content: Union[str, Element, List[str], List[Element]] = "",
) -> bytes:
    """Creates an OSP response XML string.

    Arguments:
        command (str): OSP Command to respond to.
        status (int): Status of the response.
        status_text (str): Status text of the response.
        content (str): Text part of the response XML element.

    Return:
        String of response in xml format.
    """
    response = Element(f'{command}_response')

    for name, value in [('status', str(status)), ('status_text', status_text)]:
        response.set(name, escape(str(value)))

    if isinstance(content, list):
        for elem in content:
            if isinstance(elem, Element):
                response.append(elem)
    elif isinstance(content, Element):
        response.append(content)
    elif content is not None:
        response.text = escape_ctrl_chars(content)

    return tostring(response, encoding='utf-8')


def get_elements_from_dict(data: Dict[str, Any]) -> List[Element]:
    """Creates a list of etree elements from a dictionary

    Args:
        Dictionary of tags and their elements.

    Return:
        List of xml elements.
    """

    responses = []

    for tag, value in data.items():
        elem = Element(tag)

        if isinstance(value, dict):
            for val in get_elements_from_dict(value):
                elem.append(val)
        elif isinstance(value, list):
            elem.text = ', '.join(value)
        elif value is not None:
            elem.text = escape_ctrl_chars(value)

        responses.append(elem)

    return responses


def elements_as_text(
    elements: Dict[str, Union[str, Dict]], indent: int = 2
) -> str:
    """Returns the elements dictionary as formatted plain text."""

    text = ""
    for elename, eledesc in elements.items():
        if isinstance(eledesc, dict):
            desc_txt = elements_as_text(eledesc, indent + 2)
            desc_txt = ''.join(['\n', desc_txt])
        elif isinstance(eledesc, str):
            desc_txt = ''.join([eledesc, '\n'])
        else:
            assert False, "Only string or dictionary"

        ele_txt = f"\t{' ' * indent}{elename: <22} {desc_txt}"

        text = ''.join([text, ele_txt])

    return text


class XmlStringHelper:
    """Class with methods to help the creation of a xml object in
    string format.
    """

    def create_element(self, elem_name: str, end: bool = False) -> bytes:
        """Get a name and create the open element of an entity.

        Arguments:
            elem_name (str): The name of the tag element.
            end (bool): Create a initial tag if False, otherwise the end tag.

        Return:
            Encoded string representing a part of an xml element.
        """
        if end:
            ret = f"</{elem_name}>"
        else:
            ret = f"<{elem_name}>"

        return ret.encode('utf-8')

    def create_response(self, command: str, end: bool = False) -> bytes:
        """Create or end an xml response.

        Arguments:
            command (str): The name of the command for the response element.
            end (bool): Create a initial tag if False, otherwise the end tag.

        Return:
            Encoded string representing a part of an xml element.
        """
        if not command:
            return

        if end:
            return (f'</{command}_response>').encode('utf-8')

        return (f'<{command}_response status="200" status_text="OK">').encode(
            'utf-8'
        )

    def add_element(
        self,
        content: Union[Element, str, list],
        xml_str: bytes = None,
        end: bool = False,
    ) -> bytes:
        """Create the initial or ending tag for a subelement, or add
        one or many xml elements

        Arguments:
            content (Element, str, list): Content to add.
            xml_str (bytes): Initial string where content to be added to.
            end (bool): Create a initial tag if False, otherwise the end tag.
                        It will be added to the xml_str.

        Return:
            Encoded string representing a part of an xml element.
        """

        if not xml_str:
            xml_str = b''

        if content:
            if isinstance(content, list):
                for elem in content:
                    xml_str = xml_str + tostring(elem, encoding='utf-8')
            elif isinstance(content, Element):
                xml_str = xml_str + tostring(content, encoding='utf-8')
            else:
                if end:
                    xml_str = xml_str + self.create_element(content, False)
                else:
                    xml_str = xml_str + self.create_element(content)

        return xml_str

    def add_attr(
        self, tag: bytes, attribute: str, value: Union[str, int] = None
    ) -> bytes:
        """Add an attribute to the beginning tag of an xml element.
        Arguments:
            tag (bytes): Tag to add the attribute to.
            attribute (str): Attribute name
            value (str): Attribute value
        Return:
            Tag in encoded string format with the given attribute
        """
        if not tag:
            return None

        if not attribute:
            return tag

        if not value:
            value = ''

        return tag[:-1] + (f" {attribute}={quoteattr(str(value))}>").encode(
            'utf-8'
        )
